[libcxx-commits] [libcxx] [libc++] Removes codecvt. (PR #72496)

Thu Nov 16 01:38:27 PST 2023

llvmbot wrote:




@llvm/pr-subscribers-libcxx

Author: Mark de Wever (mordante)

<details>
<summary>Changes</summary>

Implements:
- P2871R3 Remove Deprecated Unicode Conversion Facets from C++26

---

Patch is 39.50 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/72496.diff


54 Files Affected:

- (modified) libcxx/docs/ReleaseNotes/18.rst (+8) 
- (modified) libcxx/docs/Status/Cxx2cPapers.csv (+1-1) 
- (modified) libcxx/docs/UsingLibcxx.rst (+10) 
- (modified) libcxx/include/__config (+4) 
- (modified) libcxx/include/codecvt (+4) 
- (modified) libcxx/modules/std/codecvt.inc (+2) 
- (added) libcxx/test/libcxx/depr/enable_removed_cpp26_features.compile.pass.cpp (+20) 
- (modified) libcxx/test/libcxx/localization/locales/locale.convenience/conversions/conversions.string/ctor_move.pass.cpp (+1-1) 
- (modified) libcxx/test/std/input.output/file.streams/fstreams/ifstream.members/buffered_reads.pass.cpp (+1-1) 
- (modified) libcxx/test/std/input.output/file.streams/fstreams/ofstream.members/buffered_writes.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/utf_sanity_check.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_mode.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_always_noconv.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_encoding.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_in.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_length.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_max_length.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_out.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_unshift.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_always_noconv.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_encoding.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_in.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_length.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_max_length.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_out.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_unshift.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_utf16_always_noconv.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_utf16_encoding.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_utf16_in.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_utf16_length.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_utf16_max_length.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_utf16_out.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_utf16_unshift.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locale.stdcvt/depr.verify.cpp (+3-2) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/ctor.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/depr.verify.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/overflow.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/pbackfail.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/rdbuf.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/state.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/test.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/underflow.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/converted.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/ctor_codecvt.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/ctor_codecvt_state.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/ctor_copy.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/ctor_err_string.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/depr.verify.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/from_bytes.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/state.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/to_bytes.pass.cpp (+1-1) 
- (modified) libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.string/types.pass.cpp (+1-1) 


``````````diff

diff --git a/libcxx/docs/ReleaseNotes/18.rst b/libcxx/docs/ReleaseNotes/18.rst
index d5df7fde5be91af..5a18050d3a1b40a 100644
--- a/libcxx/docs/ReleaseNotes/18.rst
+++ b/libcxx/docs/ReleaseNotes/18.rst
@@ -48,6 +48,7 @@ Implemented Papers
 - P2538R1 - ADL-proof ``std::projected``
 - P2614R2 - Deprecate ``numeric_limits::has_denorm``
 - P0053R7 - C++ Synchronized Buffered Ostream (in the experimental library)
+- P2871R3 - Remove Deprecated Unicode Conversion Facets from C++26
 
 
 Improvements and New Features
@@ -68,6 +69,13 @@ Improvements and New Features
   on a per translation unit basis using the ``_LIBCPP_HARDENING_MODE`` macro. See :ref:`the hardening documentation
   <using-hardening-modes>` for more details.
 
+- The ``_LIBCPP_ENABLE_CXX26_REMOVED_FEATURES`` macro has been added to allow
+  re-enabling the removed features in C++26.
+
+- The ``_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT`` macro has been added to make
+  the declarations in ``<codecvt>`` available.
+
+
 Deprecations and Removals
 -------------------------
 
diff --git a/libcxx/docs/Status/Cxx2cPapers.csv b/libcxx/docs/Status/Cxx2cPapers.csv
index eb5398f66d0e0c1..63ea9a79534bf92 100644
--- a/libcxx/docs/Status/Cxx2cPapers.csv
+++ b/libcxx/docs/Status/Cxx2cPapers.csv
@@ -38,7 +38,7 @@
 "`P2821R5 <https://wg21.link/P2821R5>`__","LWG","``span.at()``","Kona November 2023","","",""
 "`P2868R3 <https://wg21.link/P2868R3>`__","LWG","Remove Deprecated ``std::allocator`` Typedef From C++26","Kona November 2023","","",""
 "`P2870R3 <https://wg21.link/P2870R3>`__","LWG","Remove ``basic_string::reserve()`` From C++26","Kona November 2023","","",""
-"`P2871R3 <https://wg21.link/P2871R3>`__","LWG","Remove Deprecated Unicode Conversion Facets from C++26","Kona November 2023","","",""
+"`P2871R3 <https://wg21.link/P2871R3>`__","LWG","Remove Deprecated Unicode Conversion Facets from C++26","Kona November 2023","|Complete|","18.0",""
 "`P2819R2 <https://wg21.link/P2819R2>`__","LWG","Add tuple protocol to complex","Kona November 2023","","",""
 "`P2937R0 <https://wg21.link/P2937R0>`__","LWG","Freestanding: Remove ``strtok``","Kona November 2023","","",""
 "`P2833R2 <https://wg21.link/P2833R2>`__","LWG","Freestanding Library: inout expected span","Kona November 2023","","",""
diff --git a/libcxx/docs/UsingLibcxx.rst b/libcxx/docs/UsingLibcxx.rst
index 24d6a7b95f5b2e4..7efb499cd0a57b8 100644
--- a/libcxx/docs/UsingLibcxx.rst
+++ b/libcxx/docs/UsingLibcxx.rst
@@ -329,6 +329,16 @@ C++20 Specific Configuration Macros
   `result_of` and `result_of_t`.
 
 
+C++26 Specific Configuration Macros
+-----------------------------------
+**_LIBCPP_ENABLE_CXX26_REMOVED_FEATURES**:
+  This macro is used to re-enable all the features removed in C++26. The effect
+  is equivalent to manually defining each macro listed below.
+
+**_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT**:
+  This macro is used to re-enable all named declarations in ``<codecvt>``.
+
+
 Libc++ Extensions
 =================
 
diff --git a/libcxx/include/__config b/libcxx/include/__config
index e8da358bb8d7cd5..6ad6aa17ced81a7 100644
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -1312,6 +1312,10 @@ __sanitizer_verify_double_ended_contiguous_container(const void*, const void*, c
 #    define _LIBCPP_ENABLE_CXX20_REMOVED_TYPE_TRAITS
 #  endif // _LIBCPP_ENABLE_CXX20_REMOVED_FEATURES
 
+#  if defined(_LIBCPP_ENABLE_CXX26_REMOVED_FEATURES)
+#    define _LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
+#  endif // _LIBCPP_ENABLE_CXX26_REMOVED_FEATURES
+
 // clang-format off
 #  define _LIBCPP_PUSH_MACROS _Pragma("push_macro(\"min\")") _Pragma("push_macro(\"max\")") _Pragma("push_macro(\"refresh()\")") _Pragma("push_macro(\"move(int, int)\")") _Pragma("push_macro(\"erase()\")")
 #  define _LIBCPP_POP_MACROS _Pragma("pop_macro(\"min\")") _Pragma("pop_macro(\"max\")") _Pragma("pop_macro(\"refresh()\")") _Pragma("pop_macro(\"move(int, int)\")") _Pragma("pop_macro(\"erase()\")")
diff --git a/libcxx/include/codecvt b/libcxx/include/codecvt
index 7a8c28d55941524..7a363280d52127c 100644
--- a/libcxx/include/codecvt
+++ b/libcxx/include/codecvt
@@ -63,6 +63,8 @@ class codecvt_utf8_utf16
 #  pragma GCC system_header
 #endif
 
+#if _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT)
+
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 enum _LIBCPP_DEPRECATED_IN_CXX17 codecvt_mode
@@ -553,6 +555,8 @@ _LIBCPP_SUPPRESS_DEPRECATED_POP
 
 _LIBCPP_END_NAMESPACE_STD
 
+#endif // _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT)
+
 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
 #  include <atomic>
 #  include <concepts>
diff --git a/libcxx/modules/std/codecvt.inc b/libcxx/modules/std/codecvt.inc
index 996036822bb40a0..277ef046349a9e0 100644
--- a/libcxx/modules/std/codecvt.inc
+++ b/libcxx/modules/std/codecvt.inc
@@ -9,10 +9,12 @@
 
 export namespace std {
 #ifndef _LIBCPP_HAS_NO_LOCALIZATION
+#  if _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT)
   using std::codecvt_mode;
 
   using std::codecvt_utf16;
   using std::codecvt_utf8;
   using std::codecvt_utf8_utf16;
+#  endif // _LIBCPP_STD_VER < 26 || defined(_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT)
 #endif // _LIBCPP_HAS_NO_LOCALIZATION
 } // namespace std
diff --git a/libcxx/test/libcxx/depr/enable_removed_cpp26_features.compile.pass.cpp b/libcxx/test/libcxx/depr/enable_removed_cpp26_features.compile.pass.cpp
new file mode 100644
index 000000000000000..d7661a043e47677
--- /dev/null
+++ b/libcxx/test/libcxx/depr/enable_removed_cpp26_features.compile.pass.cpp
@@ -0,0 +1,20 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// Test that defining _LIBCPP_ENABLE_CXX26_REMOVED_FEATURES correctly defines
+// _LIBCPP_ENABLE_CXX26_REMOVED_FOO for each individual component macro.
+
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_ENABLE_CXX26_REMOVED_FEATURES
+
+#include <__config>
+
+#include "test_macros.h"
+
+#ifndef _LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
+#  error _LIBCPP_ENABLE_CXX26_REMOVED_CODECVT must be defined
+#endif
diff --git a/libcxx/test/libcxx/localization/locales/locale.convenience/conversions/conversions.string/ctor_move.pass.cpp b/libcxx/test/libcxx/localization/locales/locale.convenience/conversions/conversions.string/ctor_move.pass.cpp
index 61e92089e4659c3..006bece21105b1a 100644
--- a/libcxx/test/libcxx/localization/locales/locale.convenience/conversions/conversions.string/ctor_move.pass.cpp
+++ b/libcxx/test/libcxx/localization/locales/locale.convenience/conversions/conversions.string/ctor_move.pass.cpp
@@ -10,7 +10,7 @@
 
 // UNSUPPORTED: c++03
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // <locale>
 
diff --git a/libcxx/test/std/input.output/file.streams/fstreams/ifstream.members/buffered_reads.pass.cpp b/libcxx/test/std/input.output/file.streams/fstreams/ifstream.members/buffered_reads.pass.cpp
index 699e6c20160febf..d57b7c20a2da272 100644
--- a/libcxx/test/std/input.output/file.streams/fstreams/ifstream.members/buffered_reads.pass.cpp
+++ b/libcxx/test/std/input.output/file.streams/fstreams/ifstream.members/buffered_reads.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 // UNSUPPORTED: c++03
 
 // <fstream>
diff --git a/libcxx/test/std/input.output/file.streams/fstreams/ofstream.members/buffered_writes.pass.cpp b/libcxx/test/std/input.output/file.streams/fstreams/ofstream.members/buffered_writes.pass.cpp
index 4aeaa42c18adeb7..e7820739505106a 100644
--- a/libcxx/test/std/input.output/file.streams/fstreams/ofstream.members/buffered_writes.pass.cpp
+++ b/libcxx/test/std/input.output/file.streams/fstreams/ofstream.members/buffered_writes.pass.cpp
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 // UNSUPPORTED: c++03
 
 // <fstream>
diff --git a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/utf_sanity_check.pass.cpp b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/utf_sanity_check.pass.cpp
index 07789cadbf6a0a9..62fce70052c2a02 100644
--- a/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/utf_sanity_check.pass.cpp
+++ b/libcxx/test/std/localization/locale.categories/category.ctype/locale.codecvt/locale.codecvt.members/utf_sanity_check.pass.cpp
@@ -9,7 +9,7 @@
 // XFAIL: availability-char8_t_support-missing
 
 // This test runs in C++20, but we have deprecated codecvt<char(16|32), char, mbstate_t> in C++20.
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // <locale>
 
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_mode.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_mode.pass.cpp
index b7020ac0f161a90..a8a05da969da897 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_mode.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_mode.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // enum codecvt_mode
 // {
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp
index c38f11df5ac4d64..229c634116796ff 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_always_noconv.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_always_noconv.pass.cpp
index f91706c77d25d67..ecf9b670895d3dd 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_always_noconv.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_always_noconv.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_encoding.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_encoding.pass.cpp
index 12bfa096924b6fc..9e16daa221fb080 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_encoding.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_encoding.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_in.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_in.pass.cpp
index 8d4f48e8f54ddcf..f9dc6f0920355b9 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_in.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_in.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_length.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_length.pass.cpp
index bf2f8af6e842800..68898957599f3d1 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_length.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_length.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_max_length.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_max_length.pass.cpp
index e9c19e51b24e621..3a5f1e972b0d080 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_max_length.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_max_length.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_out.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_out.pass.cpp
index 24b1d22881b4754..951e9cb51de7096 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_out.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_out.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_unshift.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_unshift.pass.cpp
index 55cbf5a7d0717ed..fa6af0a7f3120a0 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_unshift.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf16_unshift.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp
index 1f06de27d9aec0c..effd8d5317eadd3 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_always_noconv.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_always_noconv.pass.cpp
index f25c8e45451054e..f6bb25b41acf0ff 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_always_noconv.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_always_noconv.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_encoding.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_encoding.pass.cpp
index 55c1c5e52f766fa..25f308170a79b9c 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_encoding.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_encoding.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_in.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_in.pass.cpp
index 9abd0868f40a783..7f56bc0073ad90e 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_in.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_in.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_length.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_length.pass.cpp
index 0d52894282bd0d1..bea2ba3d15768aa 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_length.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_length.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_max_length.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_max_length.pass.cpp
index 32fdde30153ec80..41e9e5cc5654ff8 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_max_length.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_max_length.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_out.pass.cpp b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_out.pass.cpp
index 22636ca08980c2d..b6f872e9068c1cc 100644
--- a/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_out.pass.cpp
+++ b/libcxx/test/std/localization/locale.stdcvt/codecvt_utf8_out.pass.cpp
@@ -8,7 +8,7 @@
 
 // <codecvt>
 
-// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS
+// ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_CODECVT
 
 // template <class Elem, unsigned long Maxcode = 0x10ffff,
 //           codecvt_mode Mode = (codecvt_mode)0>
diff --git a/libcxx/test/std/localization/locale.stdc...
[truncated]

``````````

</details>


https://github.com/llvm/llvm-project/pull/72496
